Aneglecting air resistance, a ball projected straight upward so it remains in the air for 10 seconds needs an initial speed of o 100 m/s. 60 m/s. 50 m/s 80 m/s. 110 m/s.

The initial velocity is 50 m/s.

(C) is correct option.

Explanation:

Given that,

Time = 10 sec

For first half,

We need to calculate the height

Using equation of motion

....(I)

For second half,

We need to calculate the time

Using equation of motion

Put the value of h from equation (I)

According to question,

Put the value of t₁ and t₂

Here, g = 10

The initial velocity is

Hence, The initial velocity is 50 m/s.

radiation

explanation:

heat is transmitted by radiation

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y