Answer:
Magnets can create electricity and electricity can create a magnetic force.
Both electric charges and magnets do not have to touch an object in order to exert a force on it.
Electromagnets use electricity to create a magnetic force.
Explanation:
Answer:
Explanation:
Given that,
Height of the bridge is 20m
Initial before he throws the rock
The height is hi = 20 m
Then, final height hitting the water
hf = 0 m
Initial speed the rock is throw
Vi = 15m/s
The final speed at which the rock hits the water
Vf = 24.8 m/s
Using conservation of energy given by the question hint
Ki + Ui = Kf + Uf
Where
Ki is initial kinetic energy
Ui is initial potential energy
Kf is final kinetic energy
Uf is final potential energy
Then,
Ki + Ui = Kf + Uf
Where
Ei = Ki + Ui
Where Ei is initial energy
Ei = ½mVi² + m•g•hi
Ei = ½m × 15² + m × 9.8 × 20
Ei = 112.5m + 196m
Ei = 308.5m J
Now,
Ef = Kf + Uf
Ef = ½mVf² + m•g•hf
Ef = ½m × 24.8² + m × 9.8 × 0
Ef = 307.52m + 0
Ef = 307.52m J
Since Ef ≈ Ei, then the rock thrown from the tip of a bridge is independent of the direction of throw
Answer:
The value is 
Explanation:
Generally the velocity attained by the sled after t = 3.10 s is mathematically evaluated using the kinematic equation as follows
Here u = 0 \ m/s
a = 13.5 
So
=> 
The is distance it covers at this time is
=> 
=> 
Now when sled stops its the final velocity is 
while the initial velocity will be the velocity after its acceleration i.e
So
Here 
, the negative sign shows that it is deceleration
So
=>
Force = mass * acceleration
10 N - 2 N = 20 kg * acceleration
8 N = 20 kg * acceleration
8 / 20 = acceleration
2/5 m/s^2 = acceleration
Answer:4.05 s
Explanation:
Given
First stone is drop from cliff and second stone is thrown with a speed of 52.92 m/s after 2.7 s
Both hit the ground at the same time
Let h be the height of cliff and it reaches after time t
For second stone
---2
Equating 1 &2 we get
