Answer:
Option B. 6.25 J/S
Explanation:
Data obtained from the question include:
t (time) = 2secs
F (force) = 50N
d (distance) = 0.25m
P (power) =?
The power can be obtained by using the formula P = workdone/time.
P = workdone / time
P = (50 x 0.25)/ 2
P = 6.25J/s
We want to find how much momentum the dumbbell has at the moment it strikes the floor. Let's use this kinematics equation:
Vf² = Vi² + 2ad
Vf is the final velocity of the dumbbell, Vi is its initial velocity, a is its acceleration, and d is the height of its fall.
Given values:
Vi = 0m/s (dumbbell starts falling from rest)
a = 10m/s² (we'll treat downward motion as positive, this doesn't affect the result as long as we keep this in mind)
d = 80×10⁻²m
Plug in the values and solve for Vf:
Vf² = 2(10)(80×10⁻²)
Vf = ±4m/s
Reject the negative root.
Vf = 4m/s
The momentum of the dumbbell is given by:
p = mv
p is its momentum, m is its mass, and v is its velocity.
Given values:
m = 10kg
v = 4m/s (from previous calculation)
Plug in the values and solve for p:
p = 10(4)
p = 40kg×m/s
Answer:
16.6 kJ/°C
Explanation:
given,
Amount of heat absorbed = 45 kJ
initial temperature, T₁ = 25.5°C
final temperature, T₂ = 28.2°C
change in temperature = T₂ - T₁
= 28.2 - 25.5 = 2.7° C
Heat capacity of the object is equal to 16.6 kJ/°C
Positive. The 1st object loses electrons and will thus have an imbalance of charge with loss of electrons.
Answer:
It's D
Explanation:
Sorry if im wrong, correct me in comments and tell them actual answer if I'm wrong.
