Answer:
1.Your friend says "no thanks" to the dinner your dad cooked and prefers to just hang out with friends instead.
2. Your teammates keep making fun of you for spending so much time studying for Friday's math test.
3. Your coworkers spend every weekend watching movies at Tim's house and invite you to join them.
4. Your friends all sign up for a free class at the gym and suggest you sign up for it, too.
Answer:
3.75 m/s south
Explanation:
Momentum before collision = momentum after collision
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
Since the car and truck stick together, v₁ = v₂.
m₁ u₁ + m₂ u₂ = (m₁ + m₂) v
Given m₁ = 1500 kg, u₁ = -15 m/s, m₂ = 4500 kg, and u₂ = 0 m/s:
(1500 kg) (-15 m/s) + (4500 kg) (0 m/s) = (1500 kg + 4500 kg) v
-22500 kg m/s = 6000 kg v
v = -3.75 m/s
The final velocity is 3.75 m/s to the south.
Answer:
When a body is placed on a table top, it exerts a force equal to its weight downwards on the table top but does not move or fall. (i) Name the force exerted ...
Answer:
Work done = 4 J
Final Kinetic Energy = 4 J
Explanation:
From the question,
Work done = force × distance
W = F×d................... Equation 1
Given: F = 4.0 N, d = 1.0 meter.
Substitute these values into equation 1
W = 4×1
W = 4 Joules.
Also,
Kenetic Energy = 1/2 × mass × velocity×velocity.
K.E = 1/2(mv²)........... (2).
But,
F = ma
Where F = 4 N, m = 1 kg.
a = 4/1 = 4 m/s².
Using,
v² = u² + 2as............. Equation 3
Where u = 0 m/s, a = 4 m/s², s = 1 m.
Substitute into equation 3
v² = 0² +2×4×1
v² = 8
v = √8 m/s.
Substitutting into equation 2
K.E = 1/2(1)(√8)²
K.E = 1/2(8)
K.E = 4 J.
Hence the work done and the Final Kinetic energy are thesame = 4 J
Answer:
The answer is D.
Explanation:
One explanation I can give you is that generally waves travel faster through denser medium because the particles are tightly packed together and so they can transfer energy faster. But to verify the answer, I used Process of Elimination because the other 3 answers are not true. Choice A is entirely true, wave speed depends on the medium it is travelling through, so there is no way choice A is correct. Choice B is wrong because for example if we take light(an EM wave), it travels at a constant speed of 3.0x10^8 m/s in a vacuum and in open space. So, that proves that air or vacuum do not affect the speed of the wave in another medium. Choice C is related to Choice B, we just proved the speed of light is constant everywhere whereas choice C says that in a vacuum the speed is halved. Good luck in your Physics class and I hope for your best!
