I.i = j.j = 1
i.j = j.i = 0
(-2i - 5j)(i -4j)
= (-2i).i + (-2i).(-4j) + (-5j).i + (-5j).(-4j)
= -2 + 0 + 0 + 20 = 18
1250kgm²/s is the motional kinetic energy of a 25kg object moving at a speed of 10m/s
Kinetic energy of an object is defined as the energy which is possessed when that is in motion. It is the energy of the kinetic mass of an object. Kinetic energy is never negative and is a scalar quantity. That is, it shows only size, not orientation.
Given to us
Mass of the object, m=25kg
Velocity of the object, v=10m/s
K.E=1/2x25x10²
=1250
Kinetic energy is directly proportional to the mass and velocity squared (K.E.) of an object. =1/2xMxV². If the mass is in kilograms and the velocity is in meters/second, then the kinetic energy is in kilograms - meters squared/second.
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Answer:
The mass of the 500 series bullet train is 181.4 tonnes.
Explanation:
The momentum is given by:

Where:
m: is the mass =?
v: is the velocity = 261.8 km/h
p: is the momentum = 13194098.64 kg*m/s
By solving the above equation for "m" we have:

Therefore, the mass of the 500 series bullet train is 181.4 tonnes.
I hope it helps you!
Answer:T=1316.21 N
Explanation:
The tension has two components: Vertical and Horizontal. The
horizontal component is ma, the vertical component is mg. Using
Pythagoras theorem, we can find the tension as:
T=((ma)^2 (mg)^2)^(1/2)
So
T=((129*2.84)^2 (129*9.8)^2)^(1/2)
T=1316.21 N
Answer:
6 m/s
Explanation:
12m / 2s = 6 m/s
Hope that's the answer you seek.