Exam 1
C
A 25kg crate is pushed across a frictionless horizontal floor with a force of 20N directed 20˚ below the horizontal. The acceleration of the crate is: A) 0.8 m/s^2 B) 470 m/s^2 C) 0.75 m/s^2 D) 0.27 m/s^2 E) 170 m/s^2
C
A 3m ladder leans against a wall and makes an angle with the wall of 28˚ as shown in the drawing. What is the height (h) above the ground where the ladder makes contact with the wall? A) 1.6m B) 1.9m C) 2.6m D) 2.1m E) 2.3m
C
A dart is thrown horizontally toward a target at 20 m/s. It hits below the target 0.1s later. The distance between the target & where the dart hits is: A) 1m B) 0.5m C) 0.05m D) 2m E) 0.1m
E
A freely falling body as a constant acceleration of 9.8m/s^2. This means that: A) The acceleration of the body increases by 9.8m/s^2 during each second B) the acceleration of the body decreases by 9.8m/s^2 during each second C) the body falls 9.8m during each second D) the body falls 9.8m during the first second E) the speed of the body increases by 9.8m/s during each second
A
A golfer drives her ball from the tee down the fairway in a high arching shot. When the ball is at the highest point of its flight, A) its velocity and acceleration are both nonzero B) its velocity and acceleration are both zero C) Insufficient Information D) its velocity is nonzero but its acceleration is zero E) its velocity is zero but its acceleration is nonzero
E
A juggler throws two balls to the same height so that one is at the halfway point going up when the other is at the halfway point coming down. At that point: A) their accelerations are equal but their velocities are equal in magnitude and opposite in direction B) their velocities and accelerations are both equal in magnitude and opposite in direction C) Their velocities are equal to their accelerations D) Their velocities and accelerations are equal E) Their velocities are equal but their accelerations are equal in magnitude and opposite in direction
B
A race car will make one lap around a circular track of radius "R." When the car has traveled halfway around the track, what is the magnitude of the car's displacement from the starting point? A) 0m B) 2R C) R D) pi x R E) 2 x pi x R
D
A shell is fired with a horizontal velocity in the positive x-direction from the top of an 80m high cliff. The shell strikes the ground 1330m from the base of the cliff. Determine the initial speed of the shell: A) 82m/s B) 170 m/s C) 9.8 m/s D) 330 m/s E) 4.0 m/s
D
A stone is released from rest from the edge of a building roof 190m above the ground. Neglecting air resistance, the speed of the stone, just before striking the ground, is: A) 120m/s B) 43m/s C) 1400m/s D) 61m/s E) 190m/s
E
An automobile manufacturer claims that its product will, starting from rest, travel 0.40km in 9.0s. What is the magnitude of the constant acceleration required to do this? A) 8.9m/s^2 B) 5.6 m/s^2 C) 4.6 m/s^2 D) 6.6 m/s^2 E) 9.9 m/s^2
B
An object is shot from the back of a railroad flatcar moving 40km/h on a straight horizontal road. The launcher is aimed upward, perpendicular to the bed of the flatcar. The object falls: A) either behind or in front of the flatcar, depending on the object's initial speed B) on the flatcar C) to the side of the flatcar D) behind the flatcar E) in front of the flatcar
A
The surface of a lake has an area of 15.5km^2. What is the area of the lake in m^2? A) 1.55E7 m^2 B) 1.55E4 m^2 C) 1.55E5 m^2 D) 1.55E8 m^2 E) 1.55E6 m^2
C
Three spring scales are attached along a straight line as shown. The scale on the left is attached to a wall. A force of 15N is applied to the scale at the right. What is the reading on the middle scale (N)? A) 5 B) 10 C) 15 D) 45 E) 0
C
Use the component method of vector addition to find the components of the resultant of the four displacements shown in the figure. The magnitudes of displacement are shown. A) 3.71 , -1.09 B) 5.45, -2.82 C) 6.93, -2.19 D) 2.19, -6.92 E) 1.09, -3.71
B
Which expression is false concerning the vectors shown in the sketch? A) C < A+B B) C = A + B C) C + A = -B D) A^2 + B^2 = C^2 E) A + B + C = 0
