Answer:
Fossils are the remains of an ancient organism or the traces of activity of such an organism. There are two types of fossils: body fossils and trace fossils. Body fossils include preserved remains of an organism (i.e. freezing, drying, petrification, permineralization, bacteria and algea).
Answer:
400 trips
Explanation:
Mechanical energy needed to climb 14 m by a man of 68 kg
= mgh
= 68 x 9.8 x 14
= 9330 J
1 Kg of fat releases 3.77 x 10⁷ J of energy
.45 kg of fat releases 1.6965 x 10⁷ J of energy
22% is converted into mechanical energy
so 22% of 1.6965 x 10⁷ J
= 3732.3 x 10³ J of mechanical energy will be available for mechanical work.
one trip of climbing of 14 m requires 9330 J of mechanical energy
no of such trip possible with given mechanical energy
= 3732.3 x 10³ / 9330
= 400 trips
<u>Complete Question:</u>
Devon has several toy car bodies and motors. The motors have the same mass, but they provide different amounts of force, as shown in this table.
The bodies have the masses shown in this table (refer attached figure).
Which motor and body should Devon use to build the car with the greatest acceleration?
motor 1, with body 1
motor 1, with body 2
motor 2, with body 1
motor 2, with body 2
<u>Answer:</u>
Devon should build the car with motor 2 and body 1 for having the greatest acceleration.
<u>Explanation:</u>
As per Newton's second law of motion, the acceleration of any object is directly proportional to the force on the object and inversely proportional to the mass of the object.
It can be seen that motor 2 has greater force than the force provided by motor 1. Similarly, the mass of body 1 is found to be lesser compared to mass of body 2. So,
It gives, the system with motor 2 and body 1 the maximum acceleration. So the car should be built with motor 2 and body 1.
Answer:
- 210 rad/s²
Explanation:
n = frequency of rotation = 3400/60 = 170/3 per sec.
angular velocity ω ( 0 ) at time 0 = 2π n = 2π x 170/3
angular velocity at time t = ω(t) = 0
now, ω²( t) = w²(o) + 2α Φ ( α = angular acceleration and Φ = angular displacement) = 2π x 48 rad.
0 = ( 2π x 170/3 )² + 2α x 48 x 2π
α = - (2π x 170 x 170 )/ (3 x 3 x 2 x 48 ) = 210 rad / s²