Answer:
8.1Ns
Explanation:
Impulse is expressed as the product of Force and time
Impulse = Ft
F is the force = 180N
Get the time using the equation of motion
v = u+at
18 = 0+F/m(t)
18 = 180/0.45(t)
18 = 400t
t = 18/400 secs
Recall that;
Impulse = Ft
Impulse = 180×18/400
Impulse = 8.1Ns
Hence the impulse imparted to the ball is 8.1Ns
An object with more mass has more kinetic energy than an object with less mass, if both objects are moving at the same speed. <em>(c)</em>
Answer:
Draw line perpendicular to mirror
Angle of incidence = angle between incident ray and perpendicular
Angle of reflection = angle between reflected ray and perpendicular
32 + 32 = 64
Angle of incidence = angle of reflection = 32 deg
Answer: 1.14 N
Explanation :
As any body submerged in a fluid, it receives an upward force equal to the weight of the fluid removed by the body, which can be expressed as follows:
Fb = δair . Vb . g = 1.29 kg/m3 . 4/3 π (0.294)3 m3. 9.8 m/s2
Fb = 1.34 N
In the downward direction, we have 2 external forces acting upon the balloon: gravity and the tension in the line, which sum must be equal to the buoyant force, as the balloon is at rest.
We can get the gravity force as follows:
Fg = (mb +mhe) g
The mass of helium can be calculated as the product of the density of the helium times the volume of the balloon (assumed to be a perfect sphere), as follows:
MHe = δHe . 4/3 π (0.294)3 m3 = 0.019 kg
Fg = (0.012 kg + 0.019 kg) . 9.8 m/s2 = 0.2 N
Equating both sides of Newton´s 2nd Law in the vertical direction:
T + Fg = Fb
T = Fb – Fg = 1.34 N – 0.2 N = 1.14 N
