Answer:
(A) She needs to move the decimal point by 3 places
Work is calculated by multiplying force by the distance that the object had moved. The applied force is 60 N, moving the object by 10 m. Thus, the work does is 600 J. For the friction force which is equal to,
100N x 0.250 = 25.0 N
the work done is,
W = (60 N - 25 N) x 10 m = 350 J
The kinetic energy of the box can be equated to this force. Thus, the answer is also 350 J.
Answer:
32.76 Volt
Explanation:
frequency, f = 400 Hz
Area of crossection, A = 13 cm²
Maximum flux density, B = 0.9 tesla
Number of turns in secondary coil, N = 70
Let the maximum induced voltage is e.
According to the Faraday's law of electromagnetic induction, the induced emf is equal to the rate of change of magnetic flux.
e = dФ/dt

Time is defined as the reciprocal of frequency.
So, e = N B A f
e = 70 x 0.9 x 13 x 10^-4 x 400
e = 32.76 volt
Answer:
Velocity is 2.17 m/s at an angle of 9.03° above X-axis.
Explanation:
Mass of object 1 , m₁ = 300 g = 0.3 kg
Mass of object 2 , m₂ = 400 g = 0.4 kg
Initial velocity of object 1 , v₁ = 5.00i-3.20j m/s
Initial velocity of object 2 , v₂ = 3.00j m/s
Mass of composite = 0.7 kg
We need to find final velocity of composite.
Here momentum is conserved.
Initial momentum = Final momentum
Initial momentum = 0.3 x (5.00i-3.20j) + 0.4 x 3.00j = 1.5 i + 0.24 j kgm/s
Final momentum = 0.7 x v = 0.7v kgm/s
Comparing
1.5 i + 0.24 j = 0.7v
v = 2.14 i + 0.34 j
Magnitude of velocity

Direction,

Velocity is 2.17 m/s at an angle of 9.03° above X-axis.