Answer:
16km/h
Explanation:
Vt=20km/h ---train speed
Vd=4km/h
Donas speed relative to ground is:
Vrd=Vt-Vd
Donas is moving in opposite direction of train .
Vrd=20km/h-4km/h
Vrd=16km/h
Answer:
False
Explanation:
The steel ball and the wooden ball do not have the same force acting on them because their masses are different. But, they have the same acceleration which is the acceleration due to gravity g = 9.8 m/s².
Using the equation of motion under freefall, s = ut +1/2gt². Since u = 0,
s = 1/2gt² ⇒ t = √(2s/g)
Since. s = height is the same for both objects, they land at the same time neglecting air resistance.
Explanation:
Power of electric kettle, P = 1 kW
Voltage, V = 220 V
(a) Electric power is given by the formula as follows :

R is resistance

(b) When connected to a 220 V supply, it takes 3 minutes for the water in the kettle to reach boiling point.
Energy supplied is given by :

P is power, 

The sun, moon, planets and stars rise in the EAST and set in the WEST.