Physics questions and answers

Physics Questions and Answers

If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.

3,336.

The magnitude of the force required to make an object of mass M move with speed V in a circular path of radius R is given by the expression.

A.

mr/v

B.

(mr) 2/v

C.

mv2/r

D.

mv/2

E.

mv/r

Correct answer is C

No explanation has been provided for this answer.

3,339.

A rocket is launched from the surface of the earth. If the radius of the earth is 6.4 x 106m and the acceleration of free fall due to gravity is 1Oms-1 calculate the escape velocity of the rocket.

A.

2.53 x 104ms-1

B.

1.13 x 104ms

C.

8.00 x 103ms-1

D.

4.23 x 103ms-1

E.

6.41 x 104ms-1

Correct answer is B

V = √2gR
V = √2 x 10 x 6.4 x 102
1.13 x 104ms

3,340.

A ball of mass 5.0kg hits a smooth vertical wall normally with a speed of 2ms-1 and rebounds with the same speed. Determine the impulse experienced by the ball

A.

20.0kg ms-1

B.

10.0kg ms-1

C.

5.0kg ms-1

D.

1.3kg ms-1

E.

0.0kg ms-1.

Correct answer is A

Impulse = Ft = mu - (-mu)
= mu + mu = 2mu = 2 x 5 x 2 = 20kgms-1