THE MINI
Alec Issigonis, 1959
The Telephone
Alexander Graham Bell, 1876
http://www.radiotimes.com/news/2013-01-08/the-50-greatest-british-inventions
Answer:
A velocity time graph shows the change of velocity of an object with respect ot time. If the slope of the graph is increasing in the postive region, it means that the velocity is changing, if the slope is decreasing, it means the the velocity is decreasing, but the object is moving in the same direction (positve direction).
If this slope intersects the graph at x-axis, it means that the body has 0 velocity and has become still. After that, if the line enters in the negative region, it means that its velocity is started to increases again, but the body is movinging in the opposite direction (negative direction)
Average force applied by the call on the glove = 780 N
Explanation:
mass of baseball=0.140 kg
initial velocity = Vi= 35 m/s
Final velocity=Vf= 0
distance traveled=11 cm= 0.11 m
using the kinematic equation Vf²= Vi²+ 2 a d
where a = acceleration
0²= 35²+ 2 a (0.11)
a=-5568.2 m/s²
Now force is given by F= ma
F= 0.140 (5568.2)
F=-780 N
The negative sign signifies that the force acts in the opposite direction.
so the average force= 780 N
Answer:
13.875 T
Explanation:
Parameters given:
Length of solenoid, L = 2.5 cm = 0.025 m
Radius of solenoid, r = 0.75 cm = 0.0075 m
Number of turns, N = 25 turns
Current, I = 1.85 A
Magnetic field, B, is given as:
B = (N*r*I) /L
B = (25 * 0.0075 * 1.85)/0.025
B = 13.875 T
Explanation:
When a man falls on a hard cemented floor his momentum reduced to zero in a very short time and hurt the man. Whereas when a man falls on a heap of sand. As sand can compress, it takes longer time for the man to hit the ground (or hard surface)
