Answer:
(a) 1.85 m/s
(b) 4.1 m/s
Explanation:
Data
- initial bullet velocity, Vbi = 837 m/s
- wooden block mass, Mw = 820 g
- initial wooden block velocity, Vwi = 0 m/s
- final bullet velocity, Vbf = 467 m/s
(a) From the conservation of momentum:
Mb*Vbi + Mw*Vwi = Mb*Vbf + Mw*Vwf
Mb*(Vbi - Vbf)/Mw = Vwf
4.1*(837 - 467)/820 = Vwf
Vwf = 1.85 m/s
(b) The speed of the center of mass speed is calculated as follows:
V = Mb/(Mb + Mw) * Vbi
V = 4.1/(4.1 + 820) * 837
V = 4.1 m/s
Answer:
<h2>5N</h2>
Explanation:
To get the magnitude of the force would require to just loosen the nut, if the force apply perpendicularly at the end of the handle, we will have to resolve the force perpendicular to the wrench. Torque is the turning effect of a body or force about a point. It is similar to moments.
Torque = Force * radius
Note that the force must be perpendicular to the wrench. On resolving the force perpendicularly to the wrench, we will have to resolve the force to the vertical.
Fy = Fsinθ
Fy = 10sin30°
Fy = 10 * 0.5
Fy = 5N
<em>Torque = Fy * r</em>
<em>Given Fy = 5N and r = 20cm = 0.2m</em>
<em>Torque = 5 * 0.2</em>
<em>Torque = 1Nm</em>
<em />
<em>Hence the magnitude of the force would require to just loosen the nut, if the force apply perpendicularly at the end of the handle is 5N</em>
Recycling glass is an energy-saving practice
Answer:
Net force = 250 N
Explanation:
Given that,
The mass of a teacher, m = 75 kg
As the parachute opens, the system experiences a 1000N drag.
We need to find the magnitude of net force acting on the teacher. 2 forces are acting on her i.e. drag force and weight.
Net force,
F = mg-D
= 75(10)-1000
= -250 N
Hence, the net force is 250 N and it is acting in the upward direction.
