Answer:
6.32m/s
Explanation:
note:Now these calculations are based in the fact that acc. due to gravity is 10m/s²
okay so I'm thinking you think the speed of a body depends on the mass of the body also,umh... well it doesn't at all!
when two bodies of different masses fall from the same height,they fall at the same time( this is just to say)
now enough of the talking let solve....
so the ball was dropped .ie from rest to the ground through a distance of 2m,
the formula for calculating the distance if a body moving in a straight line is given by:
S=ut + ½at² where u is initial velocity, a is acceleration ( of the body or due to gravity, but since its falling freely under the influence of gravity its " we use the acceleration due to gravity ,which is 10m/s²) and t is the time taken to cover the distance.
from our question the ball was dropped from rest thus its u is 0 therefore we use this equation to find the time it took to touch ground (S=½at²)
solving ....
we get t to be 0.632s
to find the speed we substitute t in the equation below:
V=u+at ,but since u=0
V=at =10•0.632=6.32m/s
therefore the speed the body uses to strike the ground is 6.32m/s
Answer:
2.4 m
Explanation:
Consider the motion along the vertical direction
= initial position of ball above the ground = 4.5 m
= time taken by the ball to hit the smokestack = 0.65 s
= initial velocity of the ball along vertical direction
= acceleration due to gravity = - 9.8 m/s²
= position of ball at the time of hitting the smokestack
Using the kinematics equation
inserting the above values
Answer:
35.20 m
Explanation:
By the law of conservation of energy we have,
where m= mass of the skier, h= 3.00 m
D= horizontal distance=13.9 m
H= maximum height attained
Also, the horizontal distance covered by the skier is
D=vt
thus, height H in terms of D is given by
H=35.20 m
Power is the rate at which energy is used in a circuit.
Answer:
36 kg
Explanation:
To answer this question, a few assumptions have to be made:
- That the temperature on the day is 35 °C
- That all the heat from the elephant is goes to warming/evaporating the water on the surface of the elephant
Energy released per hour = 2500 J/s * 3600 s = 9 000 000 J
Q = mcΔT
9 000 000 J= m *4.186 J/g-K * (373K - 308K) + m*2260 J/g
m = 36 000 g = 36 kg