(امتحان لايف (23نوفمبر physics | unit1 less2

?is the gravitational force between two bodies of masses ?1and ?2 separated by distance ? and it is given by ?=???/?2,what is the unit of the gravitational constant, ??

a)?²?^-1  

 b)?^-2?? 

  c) ?^-1?³T^-2

 d) ?⁰?^-2?     

Two physical quantities,?and ?,have the dimensional formula ??-1.The physical quantity ? has the dimensional formula ??-2.According to the equation ?=(?−?)/?,what is the dimensional formula for the physical quantity ??

a)??^-1

 b)?^-2??

 c) ?⁰?⁰T

 d) ?⁰?^-2?     

The relation between the distance an object travels and the time it takes to travel this distance can be written as ?=??+??What is the dimensional formula for ?and that for ? respectively?

a)??-1,??-2

b) ?⁰?^-1,??^-2

c)?^-1,?²

d) ?⁰?^-1,?⁰?^-2

Two physical quantities, ?and ?,have the same dimensional formula, which is ??-1?Then, the dimensional formula of the quantity 5?+2? is .

a)?²?^-1

b)?^-2?? 

c) ??-1T2

d) ?⁰?^-2?  

Any object of mass ?moving with a constant angular velocity in a circular path of radius ? experiences a centripetal force ?=?? ⁿ/?.Find the value of the power, ?,using the dimensional formula.

1 mg equals ………………
a) 10 ⁶ kg 

 b)10 ^-6kg 

 c)10 -4g  

d)10 ^-3g

A road is 0.75×10⁴m long. Which of the following is the equal to the length of the road?

The area of the top of a table with sides of 1.2m and 0.9m equals …….cm2

A piece of dust has a mass of 0.0065 g.What is the mass of the piece of dust expressed in standard form to one decimal place?

a)6.5×10³ g               b) 6.5×10⁶ g                   c)6.5×10^-3 g            d) 6.5×10^-6g

A rectangle has side lengths of 0.02 m and 0.004 m.Calculate the area of the rectangle.

a)80 mm²

b) 8 μm²

c)80 nm²

d) 8 nm²

The relative error in measuring the area of a room is 0.06 and the real area is 30 m² , then the absolute error in its area is ………..

The relative error in measuring resultant force acting on a body is 4%. If the relative error in measuring mass is 2% , then the relative error in measuring the acceleration of the body is ………… (Acceleration =force/mass).

The mass of an object is measured by using a scale and found to be (15±0.3) kg.So, the type of measurement is  and the percentage of error in the measurement is .

If y = (10 ± 0.2) cm ، and x = (5±0.1) cm , the absolute error and Relative error    2x + y

If M = M1 + M2, M = (100 ± 5) Kg, real value of M1 = 40 kg, r (of M2) = 0.04, M1 =………….

the relative error in estimating the volume of a cube of side length 5 cm given that the relative error in estimating its length is (0.01 cm).

An object moves along the circumference of a circle of radius (r). its displacement when it moves a half revolution is

An athelete covers a distance 250m to East, then returned 100m to west. Thus then displacement of the athelete is …………

Displacement mayn’t be  …………….distance.

The resultant of two vectors equal zero.

Two vectors are equal in magnitude but in opposite direction,when one of them inverted its direction the resultant .

A small air craft had departed the airport. After a while, the pilot reported the airport tower that the craft is at 215 km away in a Northern East direction that makes an angle 22° to East. How far the craft was from the tower; to the East and to the North?

When does the scalar product of two vectors be equal zero ?when angle between them

When does the cross product of two vectors be equal zero ?when angle between them

If the ratio between the dot product and the cross product is 7:10 ,the angle between the two vectors.