Question

A body completes one round of a circular path of radius 14m in 10 seconds. Calculate its average speed and average velocity at the end of one round.

5. a) List two conditions which need to be satisfied for work to be done on an object

b) What should be the mass of a man, If he does 2500J of work in climbing a tree 5m tall?​

Answer 1

----->

Given,

$Radius = 14 m$

Circumference = 2πr

= 2 × 3.14 × 14

= 87.92 m

$Average \: speed = \frac{distance}{time}$

$Average \: speed = \frac{87.92}{10}$

$Average \: speed = 8.79 \: m/sec$

$Average \: Velocity = 0$

( because displacement is zero )

--->

Two conditions need to be satisfied for work to be done :-

1. Force should act on the object.

2. Object must be displaced.

--->

Mass of the man = ?

Potential Energy = 2500J

Height = 5m

g = 10 m/sec2

Potential Energy = mgh

2500 = m × 10 × 5

2500 = 50 × m

$mass = \frac{2500}{50}$

$mass = 50 kg$

hope helpful....