K.E = 1/2 mv²
800 = 1/2 ×12 ×v²
800 = 6 v²
800 / 6 = v²
= 133.4 =v²
√133.4 = √v²
11.5 = v²
I hope this answer is correct.
The number of heat units needed to raise the temperature of a body by one degree.
Answer:
= 7.07 m
Explanation:
The Tarzan reaches bottom of swing after descending 2.5 m,
change in his potential energy equals his kinetic energy at bottom of swing
m g h = (1/2) m v² ,
hence speed v of Tarzan at bottom of swing is given as
v = ( 2 g h )1/2
= ( 2 × 9.8 × 2.5 )1/2
= 7 m/s
At the bottom of swing, if the vine breaks, then he is moving with horizontal velocity 7 m/s in gravitational field.
If vertical distance from ground to bottom of swing is 5 m, then time t for Tarzan to reach ground is given by
S = (1/2)g t2 or t = (2S/g)1/2
= ( 2 × 5 / 9.8 )1/2
= 1.01 s
Horizontal distance traveled by Tarzan = 1.01 × 7
= 7.07 m
