Answer:
Explanation:
Mass =11.2kg
Constant velocity =3.3m/s
μk=0.25
Since the body is moving in constant velocity, then the acceleration is zero(0).
ΣF = Σ(ma)
The normal force acting on the body is upward and the weight is acting downward
Then ΣFy=0
Therefore, N=W
W=mg=11.2×9.8=109.76N
So, N=W=109.76N
Frictional force is given as
Fr=μkN
Fr=0.25×109.76
Fr=27.44N
Frictional force acting against the motion is 27.44N
Then the forward force moving the body forward
ΣF = Σ(ma)
Since a = 0
Then,
ΣF = 0
F-Fr=0
Then F=Fr
So the force moving the body forward is 27.44N
Answer:
A.
Explanation:
an atom that has most of its mass is electrons.
Answer:
mgh₁ + ½mv₁² = mgh₂ + ½mv₂²
Explanation:
Initial total energy = final total energy
PE₁ + KE₁ = PE₂ + KE₂
mgh₁ + ½mv₁² = mgh₂ + ½mv₂²
Answer:
(A) Q = 321.1C (B) I = 42.8A
Explanation:
(a)Given I = 55A−(0.65A/s2)t²
I = dQ/dt
dQ = I×dt
To get an expression for Q we integrate with respect to t.
So Q = ∫I×dt =∫[55−(0.65)t²]dt
Q = [55t – 0.65/3×t³]
Q between t=0 and t= 7.5s
Q = [55×(7.5 – 0) – 0.65/3(7.5³– 0³)]
Q = 321.1C
(b) For a constant current I in the same time interval
I = Q/t = 321.1/7.5 = 42.8A.