Answer:
Explanation:
a )
We shall apply the concept of impulse .
Impulse = force x time = change in momentum
= 5 x 4 = 2 ( V - 3 ) , where V is final velocity of the object
20 = 2V - 6
V = 13 m /s
b )
Impulse applied = - 7 x 4 = - 28 kg m/s ( negative as direction of force is opposite motion )
If v be the final velocity
2 x 3 - 28 = 2 v ( initial momentum - change in momentum = final momentum )
- 22 = 2v
v = - 11 m /s
object will move with 11 m /s in opposite direction .
Answer:
1.10m/s
2.0.1m
3.5Hz
Explanation:
v=velocity, f=frequency and T=wavelength
1.v=ft
v=2x5
=10m
2.v=ft
100=1000T
divide both sides by 1000
T=0.1m
3.v=fT
25=5f
divide both sides by 5
f=5Hz
Answer:
d) The stone will have about 50 joules of kinetic energy and 0 joules of potential energy .
Explanation:
Given :
Initial Potential energy ,
.
Initial Kinetic energy ,
. ( because ball is in rest )
Now , we know , kinetic energy is maximum when an object reaches ground .
Also , potential energy is zero when an object is in ground .
We know , by conservation of energy :
Initial total energy = Final total energy

Therefore , option d) is correct .
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vo = 25 m/sec
<span>vf = 0 m/sec </span>
<span>Fμ = 7100 N (Force due to friction) </span>
<span>Fg = 14700 N </span>
<span>With the force due to gravity, you can find the mass of the car: </span>
<span>F = ma </span>
<span>14700 N = m (9.8 m/sec²) </span>
<span>m = 1500 kg </span>
<span>Now, we can use the equation again to find the deacceleration due to friction: </span>
<span>F = ma </span>
<span>7100 N = (1500 kg) a </span>
<span>a = 4.73333333333 m/sec² </span>
<span>And now, we can use a velocity formula to find the distance traveled: </span>
<span>vf² = vo² + 2a∆d </span>
<span>0 = (25 m/sec)² + 2 (-4.73333333333 m/sec²) ∆d </span>
<span>0 = 625 m²/sec² + (-9.466666666667 m/sec²) ∆d </span>
<span>-625 m²/sec² = (-9.466666666667 m/sec²) ∆d </span>
<span>∆d = 66.0211267605634 m </span>
<span>∆d = 66.02 m</span>