Physics.

A 30-N box is pulled upward 6.0 m along the surface of a ramp that rises at 37 degrees above the horizontal. How much work does gravity do on the box during this process?

-110 J

A forklift pushes a 100-kg crate, starting from rest, with a horizontal force of magnitude F. The graph in the figure shows the x component of this force as a function of time. What is the instantaneous velocity of the crate at time t = 10s?

-75 cm/s

A heavy sled and a light sled, both moving horizontally with he same kinetic energy, suddenly slide onto a rough patch of snow and eventually come to a stop. The coefficient of kinetic friction between the sleds and the rough snow is the same for both of them. Which of the following statements about these sleds are correct? (There could be more than one correct choice.)

-The friction from the snow will do the same amount of work on both sleds. -On the rough snow, the change in kinetic energy will be the same for both sleds. -The light sled will slide farther on the rough snow than the heavy sled.

A heavy stone and a light stone are released from rest in such away that they both have the same amount of gravitational potential energy just as they are released. Air resistance is negligible small. Which of the following statements about these stones are correct? (There could be more than one correct choice.)

-The initial height of the light stone is greater than the initial height of the heavy stone. -Just as it reaches the ground, the light stone is traveling faster than the heavy stone. -The stones both have the same kinetic energy just as they reach the ground.

A heavy dart and a light dart are launched horizontally on a frictionless table by identical ideal springs. Both springs were initially compressed by the same amount. Which of the following statements about these darts are correct? (There could be more than one correct choice.)

-The lighter dart leaves the spring moving faster than the heavy dart. -The darts both have the same kinetic energy just as they move free of the spring. Both darts had the same initial elastic potential energy.

A stone initially moving at 8.0 m/s on a level surface comes to rest due to friction after it travels 11 m. What is the coefficient of kinetic friction between the stone and the surface?

0.30

How much work is required to stretch an ideal spring of spring constant (force constant) 40 N/m from x = 0.20 m to x = 0.25 m is the unstretched position is at x = 0.00 m?

0.45 J

A 1500-kg car moving at 25 m/s hits an initially uncompressed horizontal ideal spring with spring constant (force constant) of 2.0 x 10^6 N/m. What is the maximum distance the spring compresses?

0.68 m

A 0.140-kg baseball is dropped from rest from a height of 2.20 m above the ground and experiences negligible air resistance as it falls. It rebounds to a height of 1.60 m. What change in the ball's momentum occurs as it rebounds from the ground?

1.70 kg*m/s upwards

A force produces power P by doing work W in a time T. What power will be produced by a force that does six time as much work in half as much time?

12P

An 8.0-g bullet is suddenly shot into a 4.0-kg block, at rest on a frictionless horizontal surface, as shown in the figure. The bullet remains lodged in the block. The block then moves against a spring and compresses it by 8.9 cm. The force constant (spring constant) of the spring is 1400 N/m. What is the magnitude of the impulse on the block (including the bullet inside) due to the spring during the entire time interval during which the block compresses the spring?

13 N*s

In a ballistics test, a 28-g bullet pierces a sand bag that is thick. If the initial bullet velocity was 55 m/s and it emerged from the sandbag moving at 18 m/s what was the magnitude of the friction force (assuming it to be constant) that the bullet experienced while it traveled through the bag?

130 N

A 1200-kg cannon suddenly fires a 100-kg cannonball at 35 m/s. What is the recoil speed of the cannon? Assume that frictional forces are negligible and the cannon is fired horizontally.

2.9 m/s

An object with a mass of 10 kg is initially at rest at the top of a frictionless inclined plane that rises at 30 degrees above the horizontal. At the top, the object is initially 8.0 m from the bottom of the incline, as shown in the figure. When the object is released from this position, it eventually stops at a distance d from the bottom of the inclined plane along a horizontal surface, as shown. The coefficient of kinetic friction between the horizontal surface and the object is .20, and air resistance is negligible. Find the distance d.

20 m

A dinner plate falls vertically to the floor and breaks up into three pieces, which slide horizontally along the floor. Immediately after the impact, a 320-g piece moves along the +x-axis with a speed of 2.00 m/s and a 355-g piece moves along the +y-axis with a speed of 1.50 m/s. The third piece has a mass of 100 g. In what direction relative to the +x-axis does the third piece move?

219.8 degrees from the +x-axis

An object initially at rest suddenly explodes in two fragments of masses 2.6 kg and 3.3 kg that move in opposite directions. If the speed of the first fragment is 3.6 m/s, find the internal energy of the explosion.

30 J

A block of mass m=34 kg and speed V is behind block of mass M=81 kg and speed of 0.50m/s, as shown in the figure. The surface is frictionless and the blocks collide and couple. After the collision, the blocks have a common speed of 0.90m/s. What is the magnitude of the impulse on the 34kg block due to the collision?

32 N*s

In the figure, a ball hangs by a very light string. What is the minimum speed of the ball at the bottom of its swing (point B) in order for it to reach point a, which is 1.0 m above the bottom of the swing?

4.4 m/s

As shown in the figure, a bullet of mass 0.010 kg moving horizontally suddenly strikes a block of wood of mass 1.5 kg that is suspended as a pendulum. The bullet lodges in the wood, and together they swing upward a vertical distance of 0.40 m. The length of the string is 2.0 m. What was the speed of the bullet just before it struck the wooden block?

420 m/s

A traveler pulls on a suitcase strap at an angle 36° above the horizontal. If 555 J of work are done by the strap while moving the suitcase a horizontal distance of 15 m, what is the tension in the strap?

46 N

A dinner plate falls vertically to the floor and breaks up into three pieces, which slide horizontally along the floor. Immediately after the impact, a 200-g piece moves along the +x- axis with a speed of 2.00 m/s, a 235-g piece moves along the +y-axis with a speed of 1.50 m/s. The third piece has a mass of 100 g. What is the speed of the third piece?

5.33 m/s

A spring-loaded dart gun is used to shoot a dart straight up into the air, and the dart reaches a maximum height of 24 meters. The same dart is shot up a second time from the same gun, but this time the spring is compressed only half as far (compared to the first shot). How far up does the dart go this time (neglect all friction and assume the spring is ideal)?

6.0 m

A 1200-kg ore cart is rolling at 10.8 m/s across a flat friction-free surface. A crane suddenly drops 858 kg of ore vertically into the cart. How fast does the cart move just after being loaded with the ore?

6.30 m/s

A block of mass m = 3.6 kg, moving on a frictionless surface with a speed vi = 9.3 m/s, makes a sudden perfectly elastic collision with a stationary block of mass M, as shown in the figure. Just after the collision, the 3.6-kg block recoils with a speed of vf = 2.7 m/s. What is the speed of V of the other block?

6.6 m/s

A heavy dart and a light dart are launched vertically by identical ideal springs. Both springs were initially compressed by the same amount. There is no significant air resistance. Which of the following statements about these darts are correct? (There could be more than one correct choice.)

At the maximum height, both darts have the same gravitational potential energy. The light dart goes higher than the heavy dart.

A truck has four times the mass of a car and is moving with the speed of the car. If Kt and Kc refer to the kinetic energies of truck and car respectively, it is correct to say that

Kt = 16Kc

In the figure, determine the character of the collision. The masses of the blocks, and the velocities before and after, are shown. The collision is

Perfectly elastic

A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The clay sticks to the wall. Which one of these objects experiences the greater momentum change?

The ball

Consider two less-than-desirable options. In the first you are driving 30 mph and crash head-on into an identical car also going 30 mph. In the second option you are driving 30 mph and crash head-on into a stationary brick wall. In neither case does your car bounce back from the thing it hits, and the collision time is the same in both cases. Which of these two situations would result in the greater impact force on your car?

The force would be the same in both cases.

A small car meshes with a large truck in a head-on collision. Which of the following statements concerning the momentum during the collision are correct? (There could be more than one correct choice.)

The momentum of the car-truck system is conserved, but the momentum of each one separately is not conserved.

A girl throws a stone from a bridge. Consider the following ways she might throw the stone. The speed of the stone as it leaves her hand is the same in each case. -Case A: Thrown straight up -Case B: Thrown straight down -Case C: Thrown out at an angle of 45 degrees above the horizontal. -Case D; Thrown straight out horizontally. In which case will the speed of the stone be greatest when it hits the water below if there is no significant air resistance?

The speed will be the same in all cases.

Three cars, car X, car Y, and car Z, begin accelerating from rest at the same time. Car X is more massive than car Y, which is more massive than car Z. The net accelerating force exerted on each car is identical. After 10 seconds, which car has the most amount of momentum?

They all have the same amount of momentum.

Joe and Bill throw identical balls vertically upward. Joe throws his ball with an initial speed twice as high as Bill. If there is no air resistance, the maximum height of Joe's ball will be

four times that of Bill's ball