Physics 1135 Test

P(33)

(a) PE = m x g x h = _kg x 9.8 x (1/2) x (_kg) (b) v = √(2 x g x h) KE = (1/2) x m x v^2

The three ways machines are used are:

(a) to change the direction of the effort (b) to multiply the effort (c) to change the distance through which the effort acts

U(80)

1.12*10^5 joules

What is the formula for a period of a pendulum?

2π x √(l/g)

What is power?

A measure of the speed at which work is done.

What is a machine?

Any device that transfers energy from its point of input to its point of use.

What is force?

Any influence capable of producing a change in the velocity of a body.

State the law of conservation of energy.

Energy can be neither created nor destroyed, but only changed from one form to another.

What is the formula for gravitational attrition?

F = G x (m1 x m2/r2)

At maximum displacement, what is the velocity of a string?

Its velocity is zero.

U(81)

MA = load/effort effort = load/MA

What is potential energy?

Stored energy or energy due to position.

What is kinetic energy?

The ability to do work because of a body's motion.

What is work?

The product of force and the distance through which the force is applied.

State the law of conservation of momentum.

The total momentum before an impact equals the total momentum after the impact.

How can scientists calculate the momentum of an invisible particle in an atomic reaction?

They calculate the difference between the known momenta of all other particles and the original momentum.

How is it possible to move a spacecraft through frictionless space?

Through the use of an anti-reaction engine.

(21) What is the formula for weight?

W = m x g

U(82)

W = m*g MA = load/effort effort = load/MA effort distance = MA*load distance E = F*s P = E/T = 2000 watts

W = m*g

_kg x 9.81m/sec^2 = 392 N

F = m*a

_kg x _m/sec^2 = 3960 N

P = m*v

_kg x_m/sec = 1040kg x m/sec

T = 2π*√(l/g)

l = T^2*g/4π^2 = 132cm

KE = (1/2) x m x v^2

m = _kg t = _sec v = 9.81*t = 699 joules