![using \: the \: formula \\ t = \frac{2u \sin( \alpha ) }{g} where \: u = initial \: speed \: \\ \alpha = angle \: of \: projection \\ g = acceleration \: due \: to \: gravity \\ \frac{2 \times 50 \times \sin(30) }{10} \\ \frac{100 \times 0.5}{10} = \frac{50}{10} = 5seconds](https://tex.z-dn.net/?f=using%20%5C%3A%20the%20%5C%3A%20formula%20%5C%5C%20t%20%3D%20%5Cfrac%7B2u%20%5Csin%28%20%5Calpha%20%29%20%7D%7Bg%7D%20where%20%5C%3A%20u%20%3D%20initial%20%5C%3A%20speed%20%5C%3A%20%5C%5C%20%5Calpha%20%3D%20angle%20%5C%3A%20of%20%5C%3A%20projection%20%5C%5C%20g%20%3D%20acceleration%20%5C%3A%20due%20%5C%3A%20to%20%5C%3A%20gravity%20%5C%5C%20%5Cfrac%7B2%20%5Ctimes%2050%20%5Ctimes%20%5Csin%2830%29%20%7D%7B10%7D%20%5C%5C%20%5Cfrac%7B100%20%5Ctimes%200.5%7D%7B10%7D%20%3D%20%5Cfrac%7B50%7D%7B10%7D%20%3D%205seconds)
Maximum height
= (Usinα)^2/2g
(50*0.5)^2/20
25^2/20
625/20
=31.25metres
horizontal distance = Range= [U^2 * sin2α]/g
[50^2 * sin60]/10
2500 * 0.8660/10
2165/10=216.5metres
So power is equal to work over time and work is force times distance, you do 5 times 3 and get 15 dividing by 2 gives us 7.5 W answer c
Answer
Gravity is what holds us down on the earth's (or moon's) surface. If you were to weigh yourself on a scale on Earth and then on the moon, the weight read on the moon would be 1/6 your earth weight
Answer:
(A) Impulse = 9Ns
(B) F = 1286N
Explanation:
Impulse = change in momentum = m(v-u)
v = 0 (the hand comes to a stop)
u = -10m/s
Mass = 0.9kg
Impulse = 0.9 ×(0- (-10))
= 9Ns
(B) F×t = Impulse
F = Impulse/ t
t = 7ms = 7×10-³
F = 9/ (7×10-³)
F = 1286N.
Answer:
5.791244495 KNm
Explanation:
The height h is given by,
Potential energy, PE is given by
PE=mgh where m is mass of the woman, g is acceleration due to gravity whose value is taken as
and h is already given hence substituting 77 Kg for m we obtain
PE=21.6567095 KNm
We also know that Kinetic energy is given by
where v is the velocity and substituting v for 20.3 we obtain
KE=15.865465 KNm
Friction work is the difference between PE and KE hence
Friction work=21.6567095 KNm-15865.465 Nm=5.791244495 KNm