Answer:
v = -0.45 m/s
Explanation:
Assuming the canoe was initially at rest with momentum L = 0
and that the dog's velocity is in the positive direction
conservation of momentum
0 = 15(1.2) + 40v
v = -0.45 m/s
Answer:
explained
Explanation:
When the intensity of light is increased on a piece of metal only the number of electron ejected will increase because all other things independent of intensity of light.
Light below certain frequency will not cause any electron emission no matter how intense.
The intensity produces more electron but does not change the maximum kinetic energy of electrons.
Work function is independent of the intensity of light, because it is an intrinsic property of a material.
Answer:
Work is done by the heart on the blood during this time is 0.04 J
Explanation:
Given :
Mass of blood pumped, m = 80 g = 0.08 kg
Initial speed of the blood, u = 0 m/s
Final speed of the blood, v = 1 m/s
Initial kinetic energy of blood is determine by the relation:
Final kinetic energy of blood is determine by the relation:
Applying work-energy theorem,
Work done = Change in kinetic energy
W = E₂ - E₁
Substitute the suitable values in the above equation.
W = 0.04 J
Either 175 N or 157 N depending upon how the value of 48° was measured from.
You didn't mention if the angle of 48° is from the lug wrench itself, or if it's from the normal to the lug wrench. So I'll solve for both cases and you'll need to select the desired answer.
Since we need a torque of 55 N·m to loosen the nut and our lug wrench is 0.47 m long, that means that we need 55 N·m / 0.47 m = 117 N of usefully applied force in order to loosen the nut. This figure will be used for both possible angles.
Ideally, the force will have a 0° degree difference from the normal and 100% of the force will be usefully applied. Any value greater than 0° will have the exerted force reduced by the cosine of the angle from the normal. Hence the term "cosine loss".
If the angle of 48° is from the normal to the lug wrench, the usefully applied power will be:
U = F*cos(48)
where
U = Useful force
F = Force applied
So solving for F and calculating gives:
U = F*cos(48)
U/cos(48) = F
117 N/0.669130606 = F
174.8537563 N = F
So 175 Newtons of force is required in this situation.
If the 48° is from the lug wrench itself, that means that the force is 90° - 48° = 42° from the normal. So doing the calculation again (this time from where we started plugging in values) we get
U/cos(42) = F
117/0.743144825 = F
157.4390294 = F
Or 157 Newtons is required for this case.
